I'm using Mockito 1.9.0. I want mock the behaviour for a single method of a class in a JUnit test, so I have
final MyClass myClassSpy = Mockito.spy(myInstance);
Mockito.when(myClassSpy.method1()).thenReturn(myResults);
The problem is, in the second line, myClassSpy.method1() is actually getting called, resulting in an exception. The only reason I'm using mocks is so that later, whenever myClassSpy.method1() is called, the real method won't be called and the myResults object will be returned.
MyClass is an interface and myInstance is an implementation of that, if that matters.
What do I need to do to correct this spying behaviour?
Let me quote the official documentation:
Important gotcha on spying real objects!
Sometimes it's impossible to use when(Object) for stubbing spies. Example:
List list = new LinkedList();
List spy = spy(list);
// Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
when(spy.get(0)).thenReturn("foo");
// You have to use doReturn() for stubbing
doReturn("foo").when(spy).get(0);
In your case it goes something like:
doReturn(resultsIWant).when(myClassSpy).method1();
In my case, using Mockito 2.0, I had to change all the any() parameters to nullable() in order to stub the real call.
My case was different from the accepted answer. I was trying to mock a package-private method for an instance that did not live in that package
package common;
public class Animal {
void packageProtected();
}
package instances;
class Dog extends Animal { }
and the test classes
package common;
public abstract class AnimalTest<T extends Animal> {
#Before
setup(){
doNothing().when(getInstance()).packageProtected();
}
abstract T getInstance();
}
package instances;
class DogTest extends AnimalTest<Dog> {
Dog getInstance(){
return spy(new Dog());
}
#Test
public void myTest(){}
}
The compilation is correct, but when it tries to setup the test, it invokes the real method instead.
Declaring the method protected or public fixes the issue, tho it's not a clean solution.
The answer by Tomasz Nurkiewicz appears not to tell the whole story!
NB Mockito version: 1.10.19.
I am very much a Mockito newb, so can't explain the following behaviour: if there's an expert out there who can improve this answer, please feel free.
The method in question here, getContentStringValue, is NOT final and NOT static.
This line does call the original method getContentStringValue:
doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), isA( ScoreDoc.class ));
This line does not call the original method getContentStringValue:
doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), any( ScoreDoc.class ));
For reasons which I can't answer, using isA() causes the intended (?) "do not call method" behaviour of doReturn to fail.
Let's look at the method signatures involved here: they are both static methods of Matchers. Both are said by the Javadoc to return null, which is a little difficult to get your head around in itself. Presumably the Class object passed as the parameter is examined but the result either never calculated or discarded. Given that null can stand for any class and that you are hoping for the mocked method not to be called, couldn't the signatures of isA( ... ) and any( ... ) just return null rather than a generic parameter* <T>?
Anyway:
public static <T> T isA(java.lang.Class<T> clazz)
public static <T> T any(java.lang.Class<T> clazz)
The API documentation does not give any clue about this. It also seems to say the need for such "do not call method" behaviour is "very rare". Personally I use this technique all the time: typically I find that mocking involves a few lines which "set the scene" ... followed by calling a method which then "plays out" the scene in the mock context which you have staged... and while you are setting up the scenery and the props the last thing you want is for the actors to enter stage left and start acting their hearts out...
But this is way beyond my pay grade... I invite explanations from any passing Mockito high priests...
* is "generic parameter" the right term?
One more possible scenario which may causing issues with spies is when you're testing spring beans (with spring test framework) or some other framework that is proxing your objects during test.
Example
#Autowired
private MonitoringDocumentsRepository repository
void test(){
repository = Mockito.spy(repository)
Mockito.doReturn(docs1, docs2)
.when(repository).findMonitoringDocuments(Mockito.nullable(MonitoringDocumentSearchRequest.class));
}
In above code both Spring and Mockito will try to proxy your MonitoringDocumentsRepository object, but Spring will be first, which will cause real call of findMonitoringDocuments method. If we debug our code just after putting a spy on repository object it will look like this inside debugger:
repository = MonitoringDocumentsRepository$$EnhancerBySpringCGLIB$$MockitoMock$
#SpyBean to the rescue
If instead #Autowired annotation we use #SpyBean annotation, we will solve above problem, the SpyBean annotation will also inject repository object but it will be firstly proxied by Mockito and will look like this inside debugger
repository = MonitoringDocumentsRepository$$MockitoMock$$EnhancerBySpringCGLIB$
and here is the code:
#SpyBean
private MonitoringDocumentsRepository repository
void test(){
Mockito.doReturn(docs1, docs2)
.when(repository).findMonitoringDocuments(Mockito.nullable(MonitoringDocumentSearchRequest.class));
}
Important gotcha on spying real objects
When stubbing a method using spies , please use doReturn() family of methods.
when(Object) would result in calling the actual method that can throw exceptions.
List spy = spy(new LinkedList());
//Incorrect , spy.get() will throw IndexOutOfBoundsException
when(spy.get(0)).thenReturn("foo");
//You have to use doReturn() for stubbing
doReturn("foo").when(spy).get(0);
I've found yet another reason for spy to call the original method.
Someone had the idea to mock a final class, and found about MockMaker:
As this works differently to our current mechanism and this one has different limitations and as we want to gather experience and user feedback, this feature had to be explicitly activated to be available ; it can be done via the mockito extension mechanism by creating the file src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker containing a single line: mock-maker-inline
Source: https://github.com/mockito/mockito/wiki/What%27s-new-in-Mockito-2#mock-the-unmockable-opt-in-mocking-of-final-classesmethods
After I merged and brought that file to my machine, my tests failed.
I just had to remove the line (or the file), and spy() worked.
One way to make sure a method from a class is not called is to override the method with a dummy.
WebFormCreatorActivity activity = spy(new WebFormCreatorActivity(clientFactory) {//spy(new WebFormCreatorActivity(clientFactory));
#Override
public void select(TreeItem i) {
log.debug("SELECT");
};
});
As mentioned in some of the comments, my method was "static" (though being called on by an instance of the class)
public class A {
static void myMethod() {...}
}
A instance = spy(new A());
verify(instance).myMethod(); // still calls the original method because it's static
Work around was make an instance method or upgrade Mockito to a newer version with some config: https://stackoverflow.com/a/62860455/32453
Bit late to the party but above solutions did not work for me , so sharing my 0.02$
Mokcito version: 1.10.19
MyClass.java
private int handleAction(List<String> argList, String action)
Test.java
MyClass spy = PowerMockito.spy(new MyClass());
Following did NOT work for me (actual method was being called):
1.
doReturn(0).when(spy , "handleAction", ListUtils.EMPTY_LIST, new String());
2.
doReturn(0).when(spy , "handleAction", any(), anyString());
3.
doReturn(0).when(spy , "handleAction", null, null);
Following WORKED:
doReturn(0).when(spy , "handleAction", any(List.class), anyString());
I am having a hard time getting this one piece of mocking figured out for my unit tests. The classes in question are all part of legacy code that I don't really have the option of changing right now (I am hoping to be able to do some refactoring in the future, but need tests now).
Here are the two classes that I am dealing with, and the specific part I am having trouble with. Class A declares an object using new and then class B uses the object. I am trying to mock the object but I keep getting the real version of it instead of the mocked version.
public class B extends A(){
...
int x = problemObj.doMethod();
}
public class A(){
...
ProblemObj problemObj = new ProblemObj();
}
Here is my test class.
#RunWith(PowerMockRunner.class)
#PrepareForTest({A.class, B.class})
public class ATest(){
private ProblemObj problemObjMock;
#Before
public void setUp(){
problemObj = PowerMockito.Mock(ProblemObj.class);
}
#Test
public void test(){
PowerMockito.whenNew(ProblemObj.class).withNoArguments().thenReturn(problemObj);
...//rest of test below here
}
}
I have done other whenNew mocking in tests and set it up the same way as this. But for some reason this object being in the superclass is really throwing me off.
Versions used are Junit:4.11, Mockito:1.9.5, Powermock: 1.6.6
I am trying to write a parameterized test case in JUnit. My code looks like this:
#RunWith(Parameterized.class)
#PrepareForTest({AR9DirectDebitFileWriterCustomization.class})
public class AR9DirectDebitFileWriterCustomizationTest2 extends AR3BasicUnitTest {
private DirectDebitExtractDetRec mockObj;
private ARApplicationContext mockAppCon;
private AR9DirectDebitFileWriterCustomization spyObj = null;
AccountDBViewData mockdbData;
AccountDBView mockdbView;
SearchInvoicesDBViewData[] mocksearchInvdbviewdatarr = new SearchInvoicesDBViewData[1];
#Before
public void setUp() throws Exception {
AR9DirectDebitFileWriterCustomization ar9Obj = new AR9DirectDebitFileWriterCustomization(mockdbView, mocksearchInvdbviewdatarr, mockdbData);
spyObj = PowerMockito.spy(ar9Obj);
}
public AR9DirectDebitFileWriterCustomizationTest2(DirectDebitExtractDetRec mockObj_from_collection, ARApplicationContext mockAppCon_from_collection) {
this.mockObj = mockObj_from_collection;
this.mockAppCon = mockAppCon_from_collection;
}
#Parameterized.Parameters
public static Collection<Object[]> getparameters() throws ACMException{
return Arrays.asList(new Object[][]{
{mock(DirectDebitExtractDetRec.class),mock(ARApplicationContext.class)}
});
}
#Test
#Parameters
public final void testAddFileRecordCustObjectARApplicationContext( ) throws Exception {
.....SOME CODE
}
Whenever I right click on the testAddFileRecordCustObjectARApplicationContext function and run it as Junit test I get an initialization error :
java.lang.Exception: No tests found matching Method
testAddFileRecordCustObjectARApplicationContext(amdocs.ar.customizationexits.handlers.helpers.AR9DirectDebitFileWriterCustomizationTest2)
from org.junit.internal.requests.ClassRequest#3fa50b at
org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:37)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.(JUnit4TestReference.java:33)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestMethodReference.(JUnit4TestMethodReference.java:25)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:54)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
After looking for several hours on internet about this issue I could not find anything meaningful. In this scenario I am using spy and powerMocktio Functionality as well.I am not sure what is the root of this error .
And interesting thing is when I run it without using Parameterised test ,it works perfectly fine.
I had very similar error:
No tests found matching data with any parameter from...
According to my observations, it is caused by another strange error:
Unable to mock class ... due to a missing dependency
Only the first I see when I run the test, and the second, when I debug it. According to https://stackoverflow.com/a/23788935/715269,
https://stackoverflow.com/a/25659518/715269, it is the bug connected to classpath reading. The problem disappears, when we upgrade JMockit to higher versions.
Hi I have a class which the invoke the run() method of a thread from the constructor of the class by calling the start() method , So please help me to Stubs the so to write the junit test cases . The class is as follows
public class MyClass extends Thread {
Student st=null;
University uni= new University();
public MyClass(Student st) {
this.st=st;
start();
}
public void run() {
uni.calculate(st);
}
}
Thanks
Take a look at the discussion here:
Testing Constructor With Powermock
It discusses sub-classing and overriding.
In general it should be considered bad practice to have to mock the class under test in order to test it. It is also hard to do since most mocking frameworks will not allow mocking a single method once in the class under test since they create wrapping proxies.
I generated some classes off of an xsd that I made from a web service response that I am calling.
I'm getting an Exception when I run a JUnit test class that reads in an InputStream from the web service call.
I'm stuck as to what the exception means, so I'm looking for some ideas on things to check:
javax.xml.bind.UnmarshalException: Unexpected element {http://bar.foo.com/bbs}:rule
I have a class in my generated classes at:
com.foo.bar.bbs.Rule
Does the Exception mean I do not have the Rule class in the proper package?
The following are some things to check:
#XmlRootElement
Check that the Rule class is annotated with #XmlRootElement:
#XmlRootElement
public class Rule {
}
#XmlElementDecl
Or that there is a corresponding #XmlElementDecl in the ObjectFactory class:
#XmlElementDecl(namespace = "http://bar.foo.com/bbs", name = "root")
public JAXBElement<Root> createCustomer(Root value) {
return new JAXBElement<BigInteger>(_ROOT_QNAME, Root.class, null, value);
}
#XmlSchema
You will also need to ensure that the namespace information is specified correctly. A package-info class was probably generated something like the following for you. Ensure the correct namespace is specified.
#XmlSchema(
namespace = "http://bar.foo.com/bbs",
elementFormDefault = XmlNsForm.QUALIFIED)
package com.foo.bar.bbs;
import javax.xml.bind.annotation.XmlNsForm;
import javax.xml.bind.annotation.XmlSchema;
Alternatively you could include the namespace in the #XmlRootElement annotation:
#XmlRootElement(namespace="http://bar.foo.com/bbs")
public class Rule {
}
For more information see:
http://bdoughan.blogspot.com/2010/08/jaxb-namespaces.html
Make sure you are unmarshalling the correct type of object.